I planted about 25 four feet tall emerald Arborvitae last summer. When I planted them, I was concerned about getting them too close to the road and subject to road salt. They looked great all last year. This spring, they are pretty brown and dry. How can I revive them and prevent this in future years?
Road salt is hard on all plants, especially arborvitae. The faster the traffic on the road the further the salt is spread. Keep sensitive plants fifty feet, not usually possible, away from the road. The first few winters are also tough on these plants. They benefit from protection from the cold and drying winter winds. A windbreak of weed barrier or burlap placed to block road salt and winter winds will reduce salt and winter damage. A heavy spring shower or thorough spring watering will help wash the salts out of the soil and reduce further damage. Do not fertilize. Let the new plantings adjust to their location before adding any more fertilizer. Make sure the arborvitae receive sufficient moisture. Don't overdo. Excess water can be just as harmful as drought. Water thoroughly so the top 12 inches is moist. Water again when the top 4-6 inches begin to dry. Mulch the soil with shredded bark or woodchips to conserve moisture, reduce competition from weeds and grass and moderate soil temperatures. I have seen badly stressed and sparse arborvitae improve after several application of Messenger. This product contains a naturally occurring hormone, harpin. This was discovered by Cornell University. They found when plants were stressed they produced harpin. This protein encouraged vigorous growth. Wait and see what happens. You may decide to replace the badly damaged plants with something more salt tolerant.